The subject matter disclosed herein relates to a system and a method for improving performance of an exhaust gas after-treatment system, and more particularly, to regenerating a catalyst to improve its nitrogen oxide (NOx) conversion efficiency.
Current emission control regulations encourage the use of catalysts in the exhaust systems of vehicles in order to convert carbon monoxide (CO), hydrocarbons (HC), and NOx produced during engine operation into less harmful exhaust gases. Vehicles equipped with diesel engines may offer the benefit of increased fuel economy. Such vehicles may benefit from exhaust after-treatment systems that employ one or more catalysts to assist in chemically converting NOx, HC, CO, and other pollutants into less harmful compounds prior to discharge of the exhaust gases to the environment.
However, in such traditional catalyst systems, soot, HC, and other undesirable species may adsorb on the surface of the catalyst, thus contaminating the catalyst and reducing its conversion efficiency. Heating the catalyst systems to a temperature sufficient to desorb or oxidize the HC, for a predetermined amount of time, may regenerate the catalyst by desorbing or oxidizing the unwanted adsorbed species, thereby removing deposits of undesirable materials from the catalyst.